Drying part of the oven
cause
1. The raw material is sagging.
2. Roller balance problem.
3. Excessive heating of the film.
Approach
1. Increase the tension (but pay attention to the change in size); use a spreader roller (a herringbone roller should be used for aluminum foil).
2. Adjust balance.
3. Rolls are reground; separate rolls are used for aqueous and aromatic solvents.